This invention relates to manually operated tools such as picks, axes, hammers, sledges and mauls generically comprised of an elongated handle which holds at one extremity a working head, and more particularly concerns means which cause the working head to be securely held to the handle.
Picks, axes, mauls and other similar manually operated impact tools are generally comprised of a wooden handle having a distal end which is inserted into a receiving channel in the working head and secured thereto by a wedge driven into the distal end of the handle from the opposite side of the receiving channel. The wedge serves to expand the portion of the handle within the receiving channel, forcing the handle into strong frictional engagement with the interior surfaces of the receiving channel. This construction, although time-honored and inexpensive, has the disadvantage that the wood of the handle dries up with attendant shrinking and loosening within the receiving channel. Also, such principle of attachment requires the preliminary step of seating the working head upon the distal end of the handle so that its axial location upon the handle is accurately achieved.
Attachment means which utilize threaded bolts that enter the receiving channel and fasten the working head to the handle are disclosed in U.S. Pat. No. 1,943,807 to Bellerine, U.S. Pat. No. 1,342,929 to Shepard, and U.S. Pat. No. 521,861 to Zeiser et al. The effect of the threaded bolt is generally to transmit an adjustable wedge-like force to the interior of the distal end of the handle, causing expansion thereof with attendant increased frictional engagement with the receiving channel. Although some earlier attachment means involve a positive abutment principle instead of frictional engagement for retaining the working head in its properly seated position, they are generally of a complex construction amenable to failure during prolonged rugged use, or involve a difficult assembly technique.
It is accordingly an object of the present invention to provide a manually operated tool comprised of an elongated handle and a working head securely affixed to one extremity of said handle.
It is another object of this invention to provide a tool as in the foregoing object wherein the means for affixing the working head to the handle involves a machine bolt.
It is a further object of the present invention to provide a tool of the aforesaid nature wherein said bolt carries positive abutment means which controls the axial position of the working head upon said handle.
It is still another object of this invention to provide a tool of the aforesaid nature which is of rugged, durable construction amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.